Gerard Mercator (1512 – 1594)

Gerard Mercator was born Gerard de Cremere in Rupelmonde (near Antwerp) on 5 March 1512.

Young Gerard learned what Latin he could in Rupelmonde, and when he was about fifteen, his uncle sent him to s'Hertogenbosch to study at a school run by the Brothers of the Common Life. One of Mercator’s teachers was the celebrated humanist Macropedius. After three and a half years with the brothers, Gerard went to Louvain, where he enrolled in the university in 1530 as one of the poor students at Castle College.

By this time, he had Latinized his name to Mercator. He studied philosophy and took his master’s degree in 1532. The problems of the creation of the Universe and the Earth interested him in particular, and this is reflected in his works written in later years.

After spending a few years in Antwerp, he returned to Louvain in c. 1535, where he took courses in mathematics under Gemma Frisius. Soon, he was recognised as an expert on the construction of mathematical instruments, as a land surveyor and, after 1537, as a cartographer. He drew his income from these activities after his marriage on August 3, 1536. He also qualified himself as a copper engraver, the first to introduce italic handwriting to this trade. The first maps, drawn and engraved by Gerard Mercator, are Palestine, 1537; the World in double heart-shaped projection, 1538; and Flanders, 1540.

In 1544, Mercator came into great danger: he was arrested on the accusation of heresy and put into jail. Thanks to the intervention of the University of Louvain, he was released after four months. In 1552, he moved with his family to Duisburg (Germany). In 1560, Mercator became a cosmographer in service of the Duke of Jülich-Cleve-Berge, and in 1563, he became a lecturer at the Grammar School of the new University in Duisburg. During this period, he made wall maps of Europe, 1554; of Loraine, 1564; the British Isles, 1564; and the famous world map with increasing latitudes, 1569. About this time, Mercator was also working on the project for a complete description of the creation, the Heavens, Earth, Sea and world history. This resulted in his Atlas, sive cosmographicae meditationes de fabrica mundi et fabricati figura. He also worked on an edition of Ptolemy’s Geographia in 1578. The first part of his book, which contains modern maps (France, Germany, and the Netherlands), appeared in 1585.

Shortly after the publication of the second part of his map book (not yet called Atlas) with the maps of Italy (1589), he had a stroke that ended his highly significant productivity. The great man passed away on 2 December 1594, leaving the responsibility of finishing the map book to his son Rumold. The final part of it appeared in 1595. Its title is Pars Altera, and it constitutes an essential part of what was then called Mercator’s Atlas.

The map of Europe and the world map in the Atlas are by Rumold Mercator. After Rumold died in 1599, the Atlas was reissued in 1602.

The plates of the maps, both of the Ptolemy edition and the Atlas, were sold in 1604 to Jodocus Hondius of Amsterdam. The following year, Hondius managed to bring out Ptolemy’s Geographia. In 1606, the first Amsterdam edition of the Mercator Atlas appeared in the next year. From then to 1638, the Atlas saw many enlarged editions in various languages.

Pieter Van den Keere (Petrus Kaerius) (1571-c.1650)

Pieter van den Keere was born in Ghent in 1571 as the son of the type-founder, Hendrik van den Keere. In 1584, he moved with his family to London for religious reasons. There, Van den Keere received training as an engraver from Jodocus Hondius, his brother-in-law. Not only the companionship with Jodocus Hondius but also the acquaintanceship with Pieter van den Berghe (Petrus Montanus), author of the text of the Germania Inferior, originates from the years of refuge in London.
Upon their settlement in Amsterdam in 1593, both Keere and Hondius embarked on a monumental project. Their collaboration resulted in the creation of a large wall map of Europe, a masterpiece that still stands as a testament to their skill and vision, dated 1595: Nova totius Europae descriptio.
In 1610, he set up a workshop in the Kalverstraat that he called ‘In den onseeckeren tijd’ (In the uncertain time). During this period, he made numerous copperplates, including maps for his Atlas of the Netherlands and the Atlas Minor published by Jodocus Hondius.
The Germania Inferior (1617) is the first original atlas of the Netherlands published in folio size. The text for the atlas, both in Dutch and in French, was written by Petrus Montanus. After 1623, Claes Jansz. Visscher bought the plates and substituted his name for Kaerius’s. In 1634, Visscher included many of these maps in his Germana Inferior.
Kaerius's fame is not only based on his atlas of the Netherlands. He is even better known as an engraver of many loose-leaf maps and as a collaborator of book publishers. His maps are found, i.e., in the Caert thresoor (Barent Langenes, 1598), Licht der Zeevaert (Blaeu, 1608), Atlas Minor (Hondius, 1628), and Caertboeck vande Midellandsche Zee (Barents, 1595).

The Janssonius Family

Joannes Janssonius (Arnhem, 1588-1664), son of the Arnhem publisher Jan Janssen, married Elisabeth Hondius, daughter of Jodocus Hondius, in Amsterdam in 1612. After his marriage, he settled down in this town as a bookseller and publisher of cartographic material. In 1618, he established himself in Amsterdam next door to Blaeu’s bookshop. He entered into serious competition with Willem Jansz. Blaeu when copying Blaeu’s Licht der Zeevaert after the expiration of the privilege in 1620. His activities concerned the publication of atlases, books, single maps, and an extensive book trade with branches in Frankfurt, Danzig, Stockholm, Copenhagen, Berlin, Koningsbergen, Geneva, and Lyon. In 1631, he began publishing atlases together with Henricus Hondius.

In the early 1640s, Henricus Hondius left the atlas publishing business to Janssonius. Competition with Joan Blaeu, Willem’s son and successor, in atlas production, prompted Janssonius to enlarge his Atlas Novus finally into a work of six volumes, into which a sea atlas and an atlas of the Old World were inserted. Other atlases published by Janssonius are Mercator’s Atlas Minor, Hornius’s historical atlas (1652), the townbooks in eight volumes (1657), Cellarius’s Atlas Coelestis and several sea atlases and pilot guides.

After the death of Joannes Janssonius, the shop and publishing firm were continued by the heirs under the direction of Johannes van Waesbergen (c. 1616-1681), son-in-law of Joannes Janssonius. Van Waesbergen added Janssonius's name to his own.

In 1676, Joannes Janssonius’s heirs sold by auction “all the remaining Atlases in Latin, French, High and Low German, as well as the Stedeboecken in Latin, in 8 volumes, bound and unbound, maps, plates belonging to the Atlas and Stedeboecken.” The copperplates from Janssonius’s atlases were afterwards sold to Schenk and Valck.